[Role of calcium antagonists in the treatment of arterial hypertension].
We have reviewed the cardiovascular actions of calcioantagonists. These drugs act through L and T channels, inhibiting calcium ions entry at the alpha 1 subunit. The union sites for dihydropiridines (DHPs) are surfacely located (N site) compared to those of diltiazem and verapamil (D and V sites). The administration of calcioantagonists induces peripheral vasodilation with decrease of blood pressure and peripheral resistance; they also act on myocardium inhibiting AV conduction and cardiac contractility. DHPs act more specifically on vascular smooth muscle than myocardium; however, no DHPs (diltiazem and verapamil) act more specifically on myocardium than peripheral vessels. Among drugs of first generation we can mention: nifedipine, diltiazem and verapamil. Among drugs of second generation we have: lacidipine and amlodipine with better tissue selectivity and longer biological half-lives. A recently introduced compound, mibefradil, acts selectively on T channels. The use of calcioantagonists is wide: coronary disease, hypertension, cardiac arrhythmias, ischemic cerebrovascular disease, cardiac failure, primary pulmonary hypertension. World Health Organization has recommended calcium antagonists as first line drugs in hypertension as done with other compounds: diuretics, betablockers, and converting enzyme inhibitors. Recent controversial studies on calcioantogonists should be assessed adequately in order to take a definitive decision.
Velasco
M
M
Unidad de Farmacología Clínica, Escuela de Medicina JM Vargas, Universidad Central de Venezuela, Caracas, Venezuela.
Negrín
C
C
D000959:Antihypertensive Agents / Q000145:classification / Q000494:pharmacology* / Q000627:therapeutic use; D002118:Calcium / Q000502:physiology; D002121:Calcium Channel Blockers / Q000145:classification / Q000494:pharmacology* / Q000627:therapeutic use; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology; D002318:Cardiovascular Diseases / Q000188:drug therapy; D004359:Drug Therapy, Combination; D006321:Heart / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers; D015220:Calcium Channels; D002118:Calcium
Papel de los antagonistas del calcio en el tratamiento de la hipertensión arterial.